Behind the scenes at the Kelsey Museum of Archaeology

Greetings, Ugly Object fans! This month’s featured artifact is not really an object. It is, rather, a somewhat unseemly chunk of … any ideas? Here’s a clue: it is a thing greater than the sum of its parts. It is made up of large fragments of yellow marble, tufa, and travertine embedded in a gray pozzolan/lime mortar. In other words, it’s a mixture of aggregate and cement, which are the necessary ingredients for — you guessed it — Roman concrete! This particular fragment of concrete was brought to Michigan in 1901 by none other than Francis Kelsey, undoubtedly for the benefit of his students. Our records say that it is in fact a piece of wall core from the Diocletian baths in Rome. That is quite a pedigree!

Although this chunk is not much to look at, it is an example of a pretty remarkable form of Roman construction technology. You can visit this and other artifacts of Roman construction on the second floor of the Kelsey Museum’s Upjohn Exhibit Wing.